Red Seal Sheet Metal Worker Practice Exam

What is the common thickness range of residential ductwork?

1. 12 to 16 gauge

2. 18 to 24 gauge

3. 24 to 30 gauge

4. 30 to 36 gauge

The correct answer is: 24 to 30 gauge

The common thickness range of residential ductwork is typically between 18 to 24 gauge. This gauge is preferred because it provides a good balance of strength and weight, making the ductwork easy to handle and install while still being robust enough to withstand operational pressures. The thicker gauge options, such as 12 to 16 gauge, are generally used in commercial applications or for ducting that needs to handle larger volumes of air or higher pressures. Thinner options like 24 to 30 gauge are usually not suitable for standard residential applications as they may not possess the integrity required for efficient airflow and can be easily damaged. Thus, 18 to 24 gauge represents the standard thickness range that strikes the right balance for residential ductwork needs.